This project is part of a continuing investigation of the efficacy, durability, and attractiveness of weight reduction programs employing large financial incentives for weight reduction. In the coming year, individuals from two populations, middle-aged men and women drawn from a general community sample and self-referred men and women, will participate in programs for weight reduction either involving large financial contracts or no contracts. Contracts will be varied in terms of the scheduling and conditions for reinforcement. The purpose is to determine the effects of differing financial incentives on program participation rates, degree of weight reduction, and maintenance of weight loss. Previous work in this project has established that financial contracting programs are effective in enhancing weight loss among some populations. This work will extend the range of populations for which the program is applicable. Maintenance effects will also be addressed in follow-up evaluations of individuals previously participating in similar programs.